Display device

ABSTRACT

A display device includes: a panel portion, on which a plurality of sub-pixels with a discrete bus line form each individual pixel, the plurality of sub-pixels that form the individual pixel being sequentially arranged in a horizontal and a vertical direction, the panel portion displaying a two-dimensional image or a three-dimensional image by application of a signal via the bus line; and a filter portion, provided on a front surface of the panel portion, that alternately changes, for each of predetermined horizontal regions, a polarization state of light passing through the panel portion. A boundary of each of the horizontal regions of the filter portion is positioned within a range of a first sub-pixel of each of the plurality of sub-pixels. The first sub-pixel displays a different image when the two-dimensional image is displayed on the panel portion to when the three-dimensional image is displayed on the panel portion.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a display device.

2. Description of the Related Art

Display devices exist in which an image displayed on a screen isperceived by a viewer as a stereoscopic three-dimensional image. Inorder to cause the viewer to perceive the image as a stereoscopicthree-dimensional image, it is necessary to display the image on thescreen using a different display method than a normal display method.One example of such a display method is a technique in which the vieweris caused to perceive an image as a stereoscopic image by changing apolarization state of an image for the right eye and of an image for theleft eye (refer to Japanese Patent Application Publication No.JP-A-10-63199, for example). By changing the polarization state of theimage for the right eye and the image for the left eye, and by theviewer wearing glasses with the polarization state changed on the leftand right (which thus enable the viewer to view the image for the righteye using his or her right eye and to view the image for the left eyeusing his or her left eye), an image displayed on the screen can beperceived as a stereoscopic three-dimensional image.

As one technique in which the polarization state is changed for theimage for the right eye and the image for the left eye, there is atechnique in which a polarization control filter is used to change thepolarization state of the image for the right eye and the image for theleft eye (refer to Japanese Patent Application Publication No.JP-A-10-63199). However, in display devices using known polarizationcontrol filters, light is insufficiently split on a boundary along whichthe polarization state of the filter changes. When the light isinsufficiently split, a phenomenon occurs in which a part of the imagefor the right eye enters into the left eye and a part of the image forthe left eye enters into the right eye (this phenomenon is known as“crosstalk”).

In known art, therefore, in order to suppress the occurrence ofcrosstalk, a method is used in which a black matrix is arranged on theboundary section along which the polarization state of the filterchanges. By inhibiting mixing of light by arranging the black matrix onthe boundary section in which the polarization state of the filterchanges, the occurrence of crosstalk can be suppressed.

SUMMARY OF THE INVENTION

In addition to displaying a three-dimensional image that is perceived bythe viewer as a stereoscopic image, this type of display device can alsodisplay a normal two-dimensional image. However, when the black matrixis arranged on the boundary section in which the polarization state ofthe polarization control filter changes, when displaying a normaltwo-dimensional image on the screen, the black matrix causesdeterioration in luminance.

In light of the foregoing, it is desirable to provide a novel andimproved display device that is capable of displaying both atwo-dimensional image and a three-dimensional image, and is furthercapable of suppressing the occurrence of crosstalk when displaying thethree-dimensional image and also avoiding deterioration in luminancewhen displaying the two-dimensional image.

According to an embodiment of the present invention, there is provided adisplay device including a panel portion, on which a plurality ofsub-pixels that each have a discrete bus line form each individualpixel, the plurality of sub-pixels that form the individual pixel beingsequentially arranged in a horizontal and a vertical direction, thepanel portion displaying one of a two-dimensional image and athree-dimensional image by application of a signal via the bus line anda filter portion that is provided on a front surface of the panelportion and that alternately changes, for each of predeterminedhorizontal regions, a polarization state of light that passes throughthe panel portion. A boundary of each of the horizontal regions of thefilter portion is positioned within a range in which a first sub-pixelof each of the plurality of sub-pixels is provided, and the firstsub-pixel displays a different image when the two-dimensional image isdisplayed on the panel portion to when the three-dimensional image isdisplayed on the panel portion.

With the above structure, on the panel portion, the plurality ofsub-pixels, which each have the discrete bus line, form each of theindividual pixels, and the plurality of sub-pixels forming each of theindividual pixels are sequentially arranged in the horizontal and thevertical directions. The panel portion displays one of thetwo-dimensional image and the three-dimensional image in accordance witha signal applied via the bus line. The filter portion, which is providedon the front surface of the panel portion, alternately changes, for eachof the predetermined horizontal regions, the polarization state of thelight that passes through the panel portion. Furthermore, the boundaryof each of the horizontal regions of the filter portion is positionedwithin the range in which the first sub-pixel of each of the pluralityof sub-pixels is provided. The first sub-pixel displays a differentimage when the two-dimensional image is displayed on the panel portionthan when the three-dimensional image is displayed on the panel portion.As a result, deterioration in luminance can be avoided when thetwo-dimensional image is displayed, and crosstalk can also be suppressedwhen the three-dimensional image is displayed.

The display device may further including a signal supply control portionthat controls supply of an image signal to the panel portion. When thethree-dimensional image is displayed on the panel portion, the signalsupply control portion supplies the image signal that causes the firstsub-pixel positioned on the boundary of each of the horizontal regionsof the filter portion to be displayed in black.

After the first sub-pixel is displayed in black, the signal supplycontrol portion may perform control such that a new signal is notsupplied to the first sub-pixel.

The display device may further including a signal supply control portionthat controls supply of an image signal to the panel portion. The signalsupply control portion changes parameters relating to correction ofpicture quality of the image signal supplied to the plurality ofsub-pixels such that the parameters are different when thetwo-dimensional image is displayed on the panel portion to when thethree-dimensional image is displayed on the panel portion.

The filter portion may be provided such that the boundary of each of thehorizontal regions is positioned on a dark line of the first sub-pixel

A length in the vertical direction of the first sub-pixel may be shorterthan a sum of lengths in the vertical direction of all the othersub-pixels in the pixel.

According to the present invention described above, it is possible toprovide a novel and improved display device that can display both atwo-dimensional image and a three-dimensional image. With the displaydevice, as the boundary of each of the horizontal regions of the filterportion is positioned within the range in which the first sub-pixel ofeach of the plurality of sub-pixels is provided, crosstalk can besuppressed when displaying the three-dimensional image, anddeterioration in luminance can also be avoided when displaying thetwo-dimensional image.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an explanatory diagram showing the outer appearance of adisplay device 100 according to an embodiment of the present invention;

FIG. 2 is an explanatory diagram showing the functional structure of thedisplay device 100 according to the embodiment of the present invention;

FIG. 3 is an explanatory diagram showing an exploded perspective view ofthe structure of an image display portion 110 according to theembodiment of the present invention;

FIG. 4 is an explanatory diagram illustrating an array of pixels on aliquid crystal panel 166 according to the embodiment of the presentinvention;

FIG. 5 is an explanatory diagram showing a light emitting state of thepixels in a case in which an image being displayed is perceived by aviewer as a stereoscopic image (a 3D image) on the display device 100according to the present embodiment;

FIG. 6 is an explanatory diagram showing a case in which boundariesbetween polarization regions 169 a and polarization regions 169 b of apolarization control filter 168 are arranged such that they are alignedwith boundaries of liquid crystal domains of sub-pixels 173 a, 175 a and177 a;

FIG. 7 is an explanatory diagram showing an example of a known displaydevice that uses a polarization control filter; and

FIG. 8 is an explanatory diagram showing an example of a polarizationcontrol filter 14 provided with black matrices 14 c.

DETAILED DESCRIPTION OF THE EMBODIMENT(S)

Hereinafter, preferred embodiments of the present invention will bedescribed in detail with reference to the appended drawings. Note that,in this specification and the appended drawings, structural elementsthat have substantially the same function and structure are denoted withthe same reference numerals, and repeated explanation of thesestructural elements is omitted.

An exemplary embodiment of the present invention will be described indetail in the following order.

1. Example of known art

2. Embodiment of present invention

2-1. Structure of display device according to embodiment of presentinvention

2-2. Functional structure of display device according to embodiment ofpresent invention

2-3. Structure of image display portion

2-4. Array of pixels on liquid crystal panel

3. Conclusion

1. Example of Known Art

First, before giving a detailed description of the exemplary embodimentof the present invention, an image display method on a display devicethat displays a three-dimensional image according to known art will bedescribed. FIG. 7 is an explanatory diagram showing an example of aknown display device that uses a polarization control filter.

FIG. 7 shows a known display device 10 that displays thethree-dimensional image, shown schematically as a cross section seenfrom a side. The known display device 10 that displays thethree-dimensional image includes a backlight 11, polarizing plates 12 aand 12 b, a liquid crystal display element 13 and a polarization controlfilter 14.

The type of known display device 10 that displays the three-dimensionalimage shown in FIG. 7 polarizes light from the backlight 11 using thepolarizing plates 12 a and 12 b and the liquid crystal display element13. Note that, by application of a signal to the liquid crystal displayelement 13, an image for the right eye and an image for the left eye arealternately displayed on scan lines.

In addition, in the display device 10, light that has passed through thepolarizing plate 12 b is circularly polarized by the polarizationcontrol filter 14 that is provided on the front surface of thepolarizing plate 12 b. The polarization control filter 14 haspolarization regions 14 a and polarization regions 14 b that each havequarter wave plates used to either right-hand circularly polarize orleft-hand circularly polarize the light that has passed through thepolarizing plate 12 b. Respective optical axes of the polarizationregions 14 a and the polarization regions 14 b intersect orthogonallywith each other, and light that forms the image for the right eye isright-hand circularly polarized, for example, while light that forms theimage' for the left eye is left-hand circularly polarized.

The circularly polarized light from the display device 10 can be seenthrough polarized glasses 20. The polarized glasses 20 are provided witha right eye image transmission portion 21 and a left eye imagetransmission portion 22. The right eye image transmission portion 21 isprovided with a quarter wave plate and a polarizing lens (not shown inthe figures) such that the right-hand circularly polarized light canpass through. The left eye image transmission portion 22 is providedwith a quarter wave plate and a polarizing lens (not shown in thefigures) such that the left-hand circularly polarized light can passthrough. The right eye image transmission portion 21 blocks off theleft-hand circularly polarized light, while the left eye imagetransmission portion 22 blocks off the right-hand circularly polarizedlight. As a result, when the viewer is wearing the polarized glasses 20,only the light that forms the image for the right eye enters the righteye and only the light that forms the image for the left eye enters theleft eye.

When the viewer sees, through the polarized glasses 20, the light fromthe display device 10 that is circularly polarized in this way, theviewer can perceive the image displayed on the display device 10 as astereoscopic three-dimensional image.

However, when the direction of the polarized light is controlled by thepolarization control filter 14 that has the two polarization regions 14a and 14 b as shown in FIG. 7, the light is not sufficiently split onboundaries between the polarization regions 14 a and the polarizationregions 14 b. When the light is insufficiently split on theseboundaries, when the viewer sees the light from the display device 10through the polarized glasses 20, crosstalk occurs, in which part of theimage for the right eye enters into the left eye and part of the imagefor the left eye enters into the right eye.

To suppress this crosstalk, a technique is adopted that uses apolarization control filter on which black matrices are arranged on theboundary sections between the polarization regions. FIG. 8 is anexplanatory diagram showing an example of the polarization controlfilter 14 that is provided with black matrices 14 c. FIG. 8 also showsan array of pixels on the liquid crystal display element 13 that is usedto display the image. The liquid crystal display element 13 includes redpixels 13 a that emit a red color, blue pixels 13 b that emit a bluecolor and green pixels 13 c that emit a green color.

FIG. 8 shows the polarization control filter 14 on which the blackmatrices 14 c are arranged in alignment with the boundary sections ofthe pixels. By using the polarization control filter 14 with the blackmatrices 14 c arranged in this way, light is sufficiently split on theboundary sections between the polarization regions 14 a and thepolarization regions 14 b. Thus, as light is sufficiently split on theboundary sections between the polarization regions 14 a and thepolarization regions 14 b, crosstalk can be suppressed when the viewersees the light from the display device 10 through the polarized glasses20.

However, when the type of polarization control filter 14 provided withthe black matrices 14 c shown in FIG. 8 is used, light is blocked off inthe sections on which the black matrices 14 c are arranged, resulting indeterioration of luminance of the image displayed on the display device10. In particular, when a normal image (a two-dimensional image) isdisplayed on the display device 10, the presence of the black matrices14 c on the polarization control filter 14 cause deterioration in theluminance.

Here, in an embodiment of the present invention that will be describedhereinafter, an explanation will be given of a display device thatsuppresses crosstalk without providing black matrices on a polarizationcontrol filter, and that also does not experience deterioration inluminance when a normal image is displayed.

2. Embodiment of Present Invention

Hereinafter, the structure of a display device 100 according to theembodiment of the present invention will be explained. First, the outerappearance of the display device 100 according to the embodiment of thepresent invention will be described. FIG. 1 is an explanatory diagramshowing the outer appearance of the display device 100 according to theembodiment of the present invention. Additionally, FIG. 1 also showspolarized glasses 200, which are used to cause a viewer to perceive animage displayed on the display device 100 as a stereoscopic image.

The display device 100 shown in FIG. 1 is provided with an image displayportion 110 that displays images. The display device 100 does not onlydisplay normal images on the image display portion 110, but can alsodisplay three-dimensional images on the image display portion 110 thatare perceived by the viewer as stereoscopic images.

The structure of the image display portion 110 will be described in moredetail later. As a simple description here, the image display portion110 includes a light source, a liquid crystal panel and a pair ofpolarizing plates that sandwich the liquid crystal panel. Light from thelight source is polarized in a predetermined direction by passingthrough the liquid crystal panel and the polarizing plates.

In addition, the image display portion 110 is provided with apolarization control filter that further circularly polarizes the lightthat has passed through the polarizing plates. The light that entersinto the polarization control filter is circularly polarized and outputin a predetermined direction by passing through the polarization controlfilter. When the viewer sees, through a right eye image transmissionportion 212 and a left eye image transmission portion 214 of thepolarized glasses 200, the light that has been circularly polarized bythe polarization control filter, the viewer can perceive the imagedisplayed on the image display portion 110 as a stereoscopic image.

On the other hand, when a normal image is displayed on the image displayportion 110, by seeing the light output from the image display portion110 as it is, the viewer can perceive the image as the normal image.

Note that, in FIG. 1, the display device 100 is portrayed as atelevision receiver, but the present invention is naturally not limitedto this example of the form of the display device 100. The displaydevice 100 according to the present invention may be, for example, amonitor that is used when connected to an electronic appliance such as apersonal computer or the like, or it may be a mobile game console, amobile telephone, or a portable music playback device and so on.

The outer appearance of the display device 100 according to theembodiment of the present invention is described above. Next, thefunctional structure of the display device 100 according to theembodiment of the present invention will be explained.

2-2. Functional Structure of Display Device According toEmbodiment ofPresent Invention

FIG. 2 is an explanatory diagram showing the functional structure of thedisplay device 100 according to the embodiment of the present invention.Hereinafter, the functional structure of the display device 100according to the embodiment of the present invention will be explainedwith reference to FIG. 2.

As shown in FIG. 2, the display device 100 according to the embodimentof the present invention includes the image display portion 110, a videosignal control portion 120 and a timing control portion 140.

The image display portion 110 displays images in the manner describedabove, and when a signal is applied from an external source, display ofimages is performed in accordance with the applied signal. The imagedisplay portion 110 includes a display panel 112, a gate driver 113, adata driver 114 and a light source 162.

The display panel 112 displays images in accordance with the signalapplied from an external source. Liquid crystal molecules having apredetermined orientation are filled in a space between transparentplates, made of glass or the like, of the display panel 112. A drivesystem of the display panel 112 may be a twisted nematic (TN) system, avertical alignment (VA) system, or an in-place-switching (IPS) system.In the following explanation, the drive system of the display panel 112is the TN system, unless otherwise specified, but it goes without sayingthat the present invention is not limited to this example. Applicationof the signal to the display panel 112 is performed by the gate driver113 and the data driver 114.

The gate driver 113 is a driver that drives a gate bus line (not shownin the figures) of the display panel 112. A signal is transmitted fromthe timing control portion 140 to the gate driver 113, and the gatedriver 113 outputs a signal to the gate bus line in accordance with thesignal transmitted from the timing control portion 140.

The data driver 114 is a driver that generates a signal that is appliedto a data line (not shown in the figures) of the display panel 112. Asignal is transmitted from the timing control portion 140 to the datadriver 114. The data driver 114 generates a signal to be applied to thedata line, in accordance with the signal transmitted from the timingcontrol portion 140, and outputs the generated signal.

The light source 162 is provided on the furthermost side of the imagedisplay portion 110 as seen from the viewer. When an image is displayedon the image display portion 110, white light that is not polarized(unpolarized light) is output from the light source 162 to the displaypanel 112 positioned on the side of the viewer.

When the video signal control portion 120 receives a video signal froman external source, the video signal control portion 120 performsvarious types of signal processing on the received video signal suchthat it is suitable for three-dimensional image display on the imagedisplay portion 110 and outputs the processed signal. The video signalon which signal processing has been performed by the video signalcontrol portion 120 is transmitted to the timing control portion 140.The signal processing by the video signal control portion 120 is, forexample, as described below.

When a video signal to display the image for the right eye on the imagedisplay portion 110 (a right eye video signal) and a video signal todisplay the image for the left eye on the image display portion 110 (aleft eye video signal) are received by the video signal control portion120, the video signal control portion 120 generates, from the tworeceived video signals, a video signal for a three-dimensional image.The video signal for the three-dimensional image is generated by thevideo signal control portion 120 such that, for example, the image forthe right eye is displayed on the odd numbered scan lines of the displaypanel in the image display portion 110 and the image for the left eye isdisplayed on the even numbered scan lines.

In accordance with the signal transmitted from the video signal controlportion 120, the timing control portion 140 generates a pulse signalthat is used to operate the gate driver 113 and the data driver 114.When the pulse signal is generated by the timing control portion 140,and the gate driver 113 and the data driver 114 receive the pulse signalgenerated by the timing control portion 140, an image corresponding tothe signal transmitted from the video signal control portion 120 isdisplayed on the display panel 112.

The functional structure of the display device 100 according to theembodiment of the present invention is described above. Next, thestructure of the image display portion 110 of the display device 100according to the embodiment of the present invention will be explained.

2-3. Structure of Image Display Portion

FIG. 3 is an explanatory diagram showing an exploded perspective view ofthe structure of the image display portion 110 according to theembodiment of the present invention. Hereinafter, the structure of theimage display portion 110 according to the embodiment of the presentinvention will be explained with reference to FIG. 3.

As shown in FIG. 3, the image display portion 110 according to theembodiment of the present invention includes the light source 162,polarizing plates 164 a and 164 b, a liquid crystal panel 166 and apolarization control filter 168. Note that the display panel 112 shownin FIG. 2 includes the polarizing plates 164 a and 164 b, the liquidcrystal panel 166 and the polarization control filter 168.

The light source 162 is provided on the furthermost side of the imagedisplay portion 110 as seen from the side of the viewer. When an imageis displayed on the image display portion 110, white light that is notpolarized (unpolarized light) is output from the light source 162 to thedisplay panel 112 positioned on the side of the viewer. The light source162 may use a light-emitting diode, for example, or may use a coldcathode tube. Note that the light source 162 shown in FIG. 3 is asurface light source, but the present invention is not limited to thisform of light source. For example, the light source may be arrangedaround the peripheral edges of the display panel 112, and may outputlight to the display panel 112 by diffusing the light from the lightsource using a diffuser panel etc. Alternatively, for example, a pointlight source and a condenser lens may be used in combination in place ofthe surface light source.

The polarizing plate 164 a is provided between the light source 162 andthe liquid crystal panel 166. The polarizing plate 164 a has atransmission axis and an absorption axis that is perpendicular to thetransmission axis. When the unpolarized white light output from thelight source 162 enters the polarizing plate 164 a, of the unpolarizedwhite light, the polarizing plate 164 a allows light that has apolarization axis parallel with the direction of the transmission axisto pass through, and blocks off light that has a polarization axisparallel with the direction of the absorption axis. The light thatpasses through the polarizing plate 164 a enters the liquid crystalpanel 166.

The liquid crystal panel 166 is an example of a panel portion of thepresent invention and is a panel in which a space between twotransparent plates, such as glass substrates, is filled with liquidcrystal molecules that have a predetermined orientation. When the drivesystem of the display panel 112 is the TN system, the space between thetwo transparent plates is filled by the liquid crystal molecules thatare twisted and oriented to a predetermined angle (ninety degrees, forexample). Note that, when the drive system of the display panel 112 isthe VA system, the liquid crystal molecules are oriented vertically withrespect to electrodes. The liquid crystal panel 166 is, for example, athin film transistor (TFT) liquid crystal display panel. In a state inwhich voltage is not applied to the liquid crystal panel 166, the lightthat enters the liquid crystal panel 166 is displaced by ninety degreesand output from the liquid crystal panel 166. On the other hand, in astate in which voltage is applied to the liquid crystal panel 166, asthe twist of the liquid crystal molecules is removed, the light thatenters the liquid crystal panel 166 is output from the liquid crystalpanel 166 as it is, in an unchanged state of polarization.

When a pulse signal is applied from the gate driver 113 and the datadriver 114, the liquid crystal panel 166 displays an image in accordancewith the pulse signal. In the present embodiment, when an image isdisplayed on the image display portion 110 such that it is perceived asa stereoscopic three-dimensional image by the viewer, the image for theright eye and the image for the left eye are alternately displayed onthe liquid crystal panel 166 one line at a time. In the presentembodiment, the image display portion 110 is structured such that theimage for the right eye is displayed on the odd numbered lines of theliquid crystal panel 166 and the image for the left eye is displayed onthe even numbered lines of the liquid crystal panel 166.

The liquid crystal panel 166 has a plurality of pixels in the horizontaldirection and the vertical direction, and the image is displayed usingthe plurality of pixels. Each single pixel is formed of a plurality ofsub-pixel electrodes that have a discrete bus line and non-linearelement. The structure of the pixels of the liquid crystal panel 166according to the present embodiment will be explained in more in detaillater. In simple terms, in the present embodiment, one pixel is formedof two sub-pixels. By controlling the display on one of these twosub-pixels, the occurrence of crosstalk can be suppressed when thethree-dimensional image is displayed, and deterioration in luminance canalso be avoided when the two-dimensional image is displayed.

Note that, as described above, the drive system of the display panel 112may be a system other than the TN system. The VA system or the IPSsystem may be used, for example. When the drive system of the displaypanel 112 is a system other than the TN system, the space between thepolarizing plates of the liquid crystal panel 166 may be filled withliquid crystal molecules that are not twisted.

The polarizing plate 164 b is provided on the front-most side of theliquid crystal panel 166 as seen from the side of the viewer. Thepolarizing plate 164 b has a transmission axis and an absorption axisthat is perpendicular to the transmission axis. The transmission axis ofthe polarizing plate 164 b orthogonally intersects the transmission axisof the polarizing plate 164 a. Therefore, the absorption axis of thepolarizing plate 164 b intersects orthogonally with the absorption axisof the polarizing plate 164 a. When the light that has passed throughthe liquid crystal panel 166 enters the polarizing plate 164 b, of thelight that has passed through the liquid crystal panel 166, thepolarizing plate 164 b allows light that has a polarization axisparallel with the direction of the transmission axis to pass through,and blocks off light that has a polarization axis parallel with thedirection of the absorption axis. The light that passes through thepolarizing plate 164 b enters the polarization control filter 168.

The polarization control filter 168, which is provided on the front-mostside of the polarizing plate 164 b as seen from the side of the viewer,performs one of either right-hand circular or left-hand circularpolarization on the light that has passed through the polarizing plate164 b. In order to perform either right-hand circular polarization orleft-hand circular polarization, the polarization control filter 168 haspolarization regions 169 a and 169 b that each has quarter wave plates.Respective optical axes of the polarization regions 169 a and thepolarization regions 169 b intersect orthogonally with each other, andlight that forms the image for the right eye is right-hand circularlypolarized, for example, by the polarization region 169 a, while lightthat forms the image for the left eye is left-hand circularly polarizedby the polarization region 169 b.

When an image that is to be viewed as a stereoscopic three-dimensionalimage by the viewer is displayed on the image display portion 110, asdescribed above, the image for the right eye and the image for the lefteye are alternately displayed on the liquid crystal panel 166 one lineat a time. Therefore, the polarization region 169 a and the polarizationregion 169 b of the polarization control filter 168 are provided suchthat they correspond to each scan line of the liquid crystal panel 166.

As described above, the image display portion 110 according to thepresent embodiment is structured such that the image for the right eyeis displayed on the odd numbered lines and the image for the left eye isdisplayed on the even numbered lines of the liquid crystal panel 166,respectively. Therefore, the polarization control filter 168 is providedon the front-most side (the side of the viewer) of the polarizing plate164 b such that the polarization regions 169 a are positioned inalignment with positions of the odd numbered lines of the liquid crystalpanel 166 and the polarization regions 169 b are positioned in alignmentwith positions of the even numbered lines of the liquid crystal panel166, respectively.

When the light that is circularly polarized by the polarization controlfilter 168 is seen by the viewer through the polarized glasses 200, theviewer perceives an image displayed on the image display portion 110 asa stereoscopic three-dimensional image.

The structure of the image display portion 110 according to theembodiment of the present invention is explained above. Next, a pixelarray on the liquid crystal panel 166 according to the embodiment of thepresent invention will be explained.

2-4. Array of Pixels on Liquid Crystal Panel

FIG. 4 is an explanatory diagram illustrating the array of pixels on theliquid crystal panel 166 according to the embodiment of the presentinvention. In FIG. 4, the polarization control filter 168 is showntogether with the liquid crystal panel 166. Hereinafter, the pixel arrayof the liquid crystal panel 166 according to the embodiment of thepresent invention will be described with reference to FIG. 4.

As shown in FIG. 4, the liquid crystal panel 166 according to theembodiment of the present invention is formed of red pixels 172 thatemit a red color, blue pixels 174 that emit a blue color and greenpixels 176 that emit a green color: The respective pixels are repeatedlyarranged in the horizontal and the vertical directions.

The red pixels 172 are formed of sub-pixels 173 a and 173 b, the bluepixels 174 are formed of sub-pixels 175 a and 175 b and the green pixels176 are formed of sub-pixels 177 a and 177 b.

As shown in FIG. 4, the sub-pixels 173 a, 175 a and 177 a have a samelength in the vertical direction, while in the horizontal direction, thesub-pixels 173 a, 175 a and 177 a are repeatedly arranged in that order.The sub-pixels 173 b, 175 b and 177 b have a same length in the verticaldirection, while in the horizontal direction, the sub-pixels 173 b, 175b and 177 b are repeatedly arranged in that order.

In the present embodiment, the sub-pixels are formed such that thelength of the sub-pixels 173 a, 175 a and 177 a in the verticaldirection is shorter than the length of the sub-pixels 173 b, 175 b and177 b in the vertical direction.

The polarization control filter 168 is also shown in FIG. 4. Forexplanatory ease, the liquid crystal panel 166 and the polarizationcontrol filter 168 are shown alongside each other in the horizontaldirection in FIG. 4, but in the actual display device 100, thepolarization control filter 168 is provided on the front surface of theliquid crystal panel 166 (the side of the viewer). The polarizationcontrol filter 168 performs either right-hand circular polarization orleft-hand circular polarization on one pixel at a time in the verticaldirection. Note that, in the present embodiment, the polarizationcontrol filter 168 performs one of right-hand circular and left-handcircular polarization on one pixel at a time in the vertical direction,but the present invention is not limited to this example.

Additionally, as shown in FIG. 4, boundaries between the polarizationregions 169 a and 169 b of the polarization control filter 168 areprovided such that they fall within ranges of the sub-pixels 173 a, 175a and 177 a.

When the display of a normal image (two-dimensional image) on thedisplay device 100 is performed, the image is displayed on the liquidcrystal panel 166 using all of the sub-pixels as shown in FIG. 4. Incontrast to the example of known art shown in FIG. 8, it can be seenthat when the normal image is displayed on the display device 100, thereare no black matrices. By displaying the normal image on the displaydevice 100 in this way, it is possible to display an image with higherluminance on the image display portion 110 than in the known displaydevice that uses black matrices on the polarization control filter.

On the other hand, when displaying an image on the display device 100that is perceived by the viewer as a stereoscopic image (athree-dimensional image), the image is displayed on the sub-pixels usinga different pattern than that used to display the two-dimensional image.FIG. 5 is an explanatory diagram showing a light emitting state of thepixels when a three-dimensional image is displayed on the display device100 according to the embodiment of the present invention. Note here thatthe polarization control filter 168 is shown together with the liquidcrystal panel 166 in FIG. 5. Similarly to FIG. 4, for explanatory ease,the liquid crystal panel 166 and the polarization control filter 168 areshown alongside each other in the horizontal direction in FIG. 5, but inthe actual display device 100, the polarization control filter 168 isprovided on the front surface of the liquid crystal panel 166 (the sideof the viewer).

As shown in FIG. 5, in the display device 100 according to the presentembodiment, when displaying an image that is perceived as a stereoscopicimage by the viewer, the color black is displayed on the sub-pixels 173a, 175 a and 177 a that are positioned on boundaries between polarizingplates 169 a and polarizing plates 169 b of the polarization controlfilter 168, while the image is displayed by the other sub-pixels 173 b,175 b and 177 b.

Note that the display of each of the sub-pixels may be controlled by thevideo signal control portion 120. In the present embodiment, whendisplaying a three-dimensional image on the image display portion 110,signal processing is performed by the video signal control portion 120such that the image for the right eye is displayed on the odd numberedlines of the liquid crystal panel 166 and the image for the left eye isdisplayed on the even numbered lines. The video signal control portion120 may then transmit a signal to the timing control portion 140 suchthat the color black is displayed on the sub-pixels 173 a, 175 a and 177a of each of the pixels.

By displaying the color black on the sub-pixels 173 a, 175 a and 177 ain this way, the black display sub-pixels 173 a, 175 a and 177 a performthe function of the black matrices of the polarization control filterused in the display device according to the example of known art. Thus,in the display device 100 according to the present embodiment, whendisplaying an image to be seen by the viewer as a stereoscopic image, itis possible to suppress the occurrence of crosstalk by displaying thesub-pixels 173 a, 175 a and 177 a in the color black.

In addition, when displaying a three-dimensional image on the imagedisplay portion 110, by displaying in black the sub-pixels 173 a, 175 aand 177 a that are shorter in the vertical direction than the othersub-pixels, the display device 100 can display three-dimensional imageswithout any loss of luminance and picture quality. Note that, in thepresent embodiment, each single pixel is formed of two sub-pixels, butthe present invention is not limited to this example, and each pixel maybe formed of three or more sub-pixels. When each pixel is formed ofthree or more sub-pixels, the sub-pixels may be formed such that thelength in the vertical direction of the sub-pixels that are displayed inblack is shorter than the sum of the lengths in the vertical directionof the other sub-pixels.

Note that, with the display device 100 according to the presentembodiment, when displaying an image to be viewed as a stereoscopicimage by the viewer, there are sub-pixels that are constantly displayedin black. As a result, when displaying a three-dimensional image on thedisplay device 100 according to the present embodiment, variousparameters relating to picture quality correction/compensation of imagesignals supplied to each of the sub-pixels can be different to thoseused when displaying two-dimensional images. These parameters relatingto picture quality include gamma correction, accurate color capture(ACC) processing and overdrive etc.

For example, taking gamma correction as an example, the parameters canbe changed such that, when displaying three-dimensional images on thedisplay device 100 according to the present embodiment, appropriategamma correction is applied in a state that excludes the sub-pixels 173a, 175 a and 177 a and such that, when displaying two-dimensionalimages, appropriate gamma correction is applied in a state that includesall the sub-pixels.

In this way, when parameters which are appropriate to the display ofthree-dimensional images and which are different to those for thedisplay of two-dimensional images are used to correct the picturequality of the image displayed on the image display portion 110, thepicture quality of the three-dimensional image displayed on the imagedisplay portion 110 can be improved.

Note that, when the drive system of the display panel 112 is a systemother than the TN system, namely, when the drive system of the displaypanel 112 is, for example, the VA system, the boundaries between thepolarization regions 169 a and the polarization regions 169 b of thepolarization control filter 168 may be arranged such that they arealigned with boundaries of liquid crystal domains of the sub-pixels 173a, 175 a and 177 a. FIG. 6 is an explanatory diagram illustrating a casein which boundaries between the polarization regions 169 a and thepolarization regions 169 b of the polarization control filter 168 arearranged such that they are aligned with boundaries of liquid crystaldomains of the sub-pixels 173 a, 175 a and 177 a. Note that in FIG. 6,the polarization control filter 168 is shown alongside the liquidcrystal panel 166. Similarly to FIG. 4 and FIG. 5, for explanatory ease,the liquid crystal panel 166 and the polarization control filter 168 areshown alongside each other in the horizontal direction in FIG. 6, but inthe actual display device 100, the polarization control filter 168 isprovided on the front surface of the liquid crystal panel 166 (the sideof the viewer).

In the example shown in FIG. 6, the polarization control filter 168 ispositioned on the front surface of the liquid crystal panel 166 suchthat domain boundaries 173 c, 175 c and 177 c of the sub-pixels 173 a,175 a and 177 a are aligned with the boundaries between the polarizationregions 169 a and the polarization regions 169 b. By positioning thepolarization control filter 168 in this way, when displaying athree-dimensional image on the image display portion 110, the influenceof the boundaries between the polarization regions 169 a and thepolarization regions 169 b can be reduced, and the occurrence ofcrosstalk can be suppressed.

The array of pixels on the liquid crystal panel 166 according to thefirst embodiment of the present invention is explained above. In thepresent embodiment, two sub-pixels are provided for each of the colorpixels, but in the present invention, the number of sub-pixels per pixelis not limited to this example, and three or more sub-pixels may beprovided.

3. Conclusion

As described above, with the display device 100 according to theembodiment of the present invention, each pixel is formed of a pluralityof sub-pixels. When a three-dimensional image is displayed on the imagedisplay portion 110, among the plurality of sub-pixels, one of thesub-pixels is displayed in black and the other pixels are used todisplay the image. Further, when displaying a two-dimensional image onthe image display portion 110, the sub-pixels that are displayed inblack during the display of the three-dimensional image are also used todisplay the two-dimensional image.

In this way, by changing the display of the sub-pixels for the displayof the two-dimensional image and the display of the three-dimensionalimage, the occurrence of crosstalk can be suppressed during the displayof the three-dimensional image without arranging black matrices on thepolarization control filter. In addition, because black matrices are notarranged on the polarization control filter, deterioration of luminanceduring the display of the two-dimensional image can also be avoided.

Furthermore, with the display device 100 according to the embodiment ofthe present invention, when the three-dimensional image is displayed onthe image display portion 110, the sub-pixels 173 a, 175 a and 177 a,which have a shorter length in the vertical direction than the othersub-pixels, are displayed in black. By displaying the sub-pixels 173 a,175 a and 177 a, which have a shorter length in the vertical directionthan the other sub-pixels, in black in this way, the display device 100can display the three-dimensional image without any impairment ofluminance and picture quality.

Moreover, with the display device 100 according to the embodiment of thepresent invention, the polarization control filter 168 may be positionedsuch that the boundaries between the polarization regions 169 a and thepolarization regions 169 b of the polarization control filter 168 arealigned with the boundaries between the liquid crystal domains of thesub-pixels 173 a, 175 a and 177 a. By positioning the polarizationcontrol filter 168 in this way, when displaying the three-dimensionalimage on the image display portion 110, the influence of the boundariesbetween the polarization regions 169 a and the polarization regions 169b can be reduced, and the occurrence of crosstalk can be suppressed.

It should be understood by those skilled in the art that variousmodifications, combinations, sub-combinations and alterations may occurdepending on design requirements and other factors insofar as they arewithin the scope of the appended claims or the equivalents thereof.

For example, in the above-described embodiment, when a three-dimensionalimage is displayed on the image display portion 110, by displaying thesub-pixels 173 a, 175 a and 177 a in black, the sub-pixels 173 a, 175 aand 177 a perform a similar function to black matrices on thepolarization control filter. However, the present invention is notlimited to this example. For example, when the sub-pixels 173 a, 175 aand 177 a are once displayed in black, by then not supplying a newsignal to (not writing into) the sub-pixels 173 a, 175 a and 177 a, thesub-pixels 173 a, 175 a and 177 a may be caused to perform a functionsimilar to that of the black matrices of the polarization control filterused on the display device according to the example of the known art.

Additionally, in the above-described embodiment, the display device 100is a liquid crystal display device that uses the liquid crystal panel166, but the present invention is not limited to this example. Insofaras the display device can display both a two-dimensional image and athree-dimensional image, the display device may be a device other than aliquid crystal display device that uses a liquid crystal panel. Forexample, the display device may be a display device that uses an organicEL panel.

The present application contains subject matter related to thatdisclosed in Japanese Priority Patent Application JP 2009-49837 filed inthe Japan Patent Office on March 2009, the entire content of which ishereby incorporated by reference.

1. A display device comprising: a panel portion, on which a plurality ofsub-pixels that each have a discrete bus line form each individualpixel, the plurality of sub-pixels that form the individual pixel beingsequentially arranged in a horizontal and a vertical direction, thepanel portion displaying one of a two-dimensional image and athree-dimensional image by application of a signal via the bus line; anda filter portion that is provided on a front surface of the panelportion and that alternately changes, for each of predeterminedhorizontal regions, a polarization state of light that passes throughthe panel portion, wherein a boundary of each of the horizontal regionsof the filter portion is positioned within a range in which a firstsub-pixel of each of the plurality of sub-pixels is provided, and thefirst sub-pixel displays a different image when the two-dimensionalimage is displayed on the panel portion to when the three-dimensionalimage is displayed on the panel portion.
 2. The display device accordingto claim 1, further comprising: a signal supply control portion thatcontrols supply of an image signal to the panel portion, wherein whenthe three-dimensional image is displayed on the panel portion, thesignal supply control portion supplies the image signal that causes thefirst sub-pixel positioned on the boundary of each of the horizontalregions of the filter portion to be displayed in black.
 3. The displaydevice according to claim 2, wherein after the first sub-pixel isdisplayed in black, the signal supply control portion performs controlsuch that a new signal is not supplied to the first sub-pixel.
 4. Thedisplay device according to claim 1, further comprising: a signal supplycontrol portion that controls supply of an image signal to the panelportion, wherein the signal supply control portion changes parametersrelating to correction of picture quality of the image signal suppliedto the plurality of sub-pixels such that the parameters are differentwhen the two-dimensional image is displayed on the panel portion to whenthe three-dimensional image is displayed on the panel portion.
 5. Thedisplay device according to claim 1, wherein the filter portion isprovided such that the boundary of each of the horizontal regions ispositioned on a dark line of the first sub-pixel.
 6. The display deviceaccording to claim 1, wherein a length in the vertical direction of thefirst sub-pixel is shorter than a sum of lengths in the verticaldirection of all the other sub-pixels in the pixel.